A Marketing Research Company Is Estimating Which of Two Soft

Multiple Choice

A marketing research company is estimating which of two soft drinks college students prefer. A random sample of 329 college students produced the following 95% confidence interval for the proportion of college students who prefer one of the colas: (.329, .474) . What additional assumptions are necessary for the interval to be valid?

A) The population proportion has an approximately normal distribution.
B) The sample was randomly selected from an approximately normal population.
C) The sample proportion equals the population proportion.
D) No additional assumptions are necessary.